Fibrous Nonwoven Web with Uniform, Directionally-Oriented Projections and a Process and Apparatus for Making the Same

ABSTRACT

A process and apparatus is used for making a fibrous nonwoven web with uniform, directionally-oriented projections by depositing fibrous material onto a first forming surface with holes positioned above a second forming surface with both forming surfaces traveling at different speeds to one another. As the fibers are deposited onto the first forming surface, a portion of the fibers are drawn down into the holes of the first forming surface forming the projections which contact the second forming surface. Due to the speed differential between the two forming surfaces the projections are uniformly skewed in the same direction. The resultant material is particularly suited for use as a wiping material which can be more abrasive in one direction but which is softer to the touch when wiped in the opposite direction thus making it a dual purpose material.

This application claims the benefit of priority from U.S. ProvisionalApplication No. 61/649,742 filed on May 21, 2012.

BACKGROUND OF THE INVENTION

The present invention is directed to fibrous nonwoven webs with uniform,directionally-oriented projections located on at least one surface ofthe formed material as well as the process and apparatus for making sucha material.

Disposable products are an ever increasing portion of the consumermarket, especially in the context of personal products such as cleaningproducts for the face and body. The same is true for products used forhousehold cleaning and other cleaning applications. A commonly desiredattribute for all such products is the cleaning ability of the productand its ability to absorb and retain fluids. Today there are many wipingproducts that are available in either a dry or wet state. A large numberof such products are relatively flat, two-dimensional products withlittle variability in the topography of the material. Other materialsare textured due to embossing of the wiping material. Still othermaterials are tufted. See, for example, U.S. Patent Application No.2003/0211802 to Keck et al. assigned to Kimberly-Clark Worldwide, Inc.which discloses three-dimensional coform nonwoven coform webs which haveprojections which increase the bulk of the nonwoven web and aid in thescrubbing and cleaning ability of the coform web. See also U.S. Pat. No.5,180,620 to Mende assigned to Mitsui Petrochemical Industries, Ltd.which discloses a nonwoven fabric comprised of meltblown fibers withprojections extending from the fabric base. Still a further example isU.S. Patent Application No. 2007/0130713 to Chen et al. and assigned toKimberly-Clark Worldwide, Inc. which discloses a cleaning wipe with atextured surface which may be used as a stand-alone product or can beincorporated into a cleaning tool. The wipe includes a base materialhaving an application face and a plurality of projections extendinggenerally transversely from the application face. The projections mayhave various shapes, including a mushroom shape. A high friction elementcan be applied to at least a portion of the projections to provideenhanced abrasive scrubbing functionality. With the mushroom-shapedembodiment the projections have a cross-sectional shape such that thehead portion extends laterally beyond and overhangs the base portion.The voids or spaces between the projections are said to be particularlywell suited for trapping hair and other difficult to retain materialsfrom the surface being cleaned. The tapered voids (tapered from the headportion of the projections towards the land areas) allow for hair andother relatively larger particulate matter to become essentially“wedged” into the void spaces, with the tapered profile of theprojections serving to “lock” the particulate matter within the voids.Yet another example of a material with a three-dimensional shape isdisclosed in U.S. Patent Application No. 2002/0132544 to Takagakiassigned to Toyoda Boshoku Corporation which spins semi-molten fibersonto a mold. U.S. Pat. No. 6,610,173 to Lindsay et al. assigned toKimberly-Clark Worldwide, Inc. discloses a method for imprinting a paperweb during a wet pressing event with asymmetrical protrusionscorresponding to the deflection conduits of a deflection member. Incertain embodiments, if substantial shear is applied to the deflectionmembers by way of differential velocity transfer, a snowplow effect canbe produced in which the moist fibers are sheared and piled up towardone side of the protrusion.

Despite the foregoing examples of products and processes for creatingsuch textured materials, there is still a need for materials that aretextured and easy to produce. The present invention is directed to amaterial which has protrusions which are directionally-oriented in onedirection in a uniform manner. In so doing, the projections can act toprovide more friction when wiped across a surface in one direction thanin another. As a result, the material will have a somewhat rougher feelwhen wiped in one direction and a smoother feel in the oppositedirection. Also disclosed is a process and apparatus for making such amaterial.

DEFINITIONS

As used herein, the term “meltblown fibers” means fibers formed byextruding a molten thermoplastic material through a plurality of fine,usually circular, die capillaries as molten threads or filaments intoconverging high velocity, usually hot, gas (e.g. air) streams whichattenuate the filaments of molten thermoplastic material to reduce theirdiameter, which may be to microfiber diameter. Thereafter, the meltblownfibers are carried by the high velocity gas stream and are deposited ona collecting surface to form a web of randomly dispersed meltblownfibers. Such a process is disclosed, for example, in U.S. Pat. No.3,849,241 to Butin, which is hereby incorporated by reference in itsentirety. Meltblown fibers are microfibers, which may be continuous ordiscontinuous, and are generally smaller than 10 microns in averagediameter. The term “meltblown” is also intended to cover other processesin which a high velocity gas (generally air) is used to aid in theformation of the filaments, such as melt spraying or centrifugalspinning.

As used herein, the term “coform nonwoven web” or “coform material”means composite materials comprising a mixture or stabilized matrix ofthermoplastic filaments and at least one additional material, usuallycalled the “second material” or the “secondary material”. As an example,coform materials may be made by a process in which at least onemeltblown die head is arranged near a chute through which the secondmaterial is added to the web while it is forming. The second materialmay be, for example, an absorbent material such as fibrous organicmaterials such as woody and non-wood pulp such as cotton, rayon,recycled paper, pulp fluff; superabsorbent materials such assuperabsorbent particles and fibers; inorganic absorbent materials andtreated polymeric staple fibers and the like; or a non-absorbentmaterial, such as non-absorbent staple fibers or non-absorbentparticles. Exemplary coform materials are disclosed in commonly assignedU.S. Pat. No. 5,350,624 to Georger et al.; U.S. Pat. No. 4,100,324 toAnderson et al.; and U.S. Pat. No. 4,818,464 to Lau et al.; the entirecontents of each is hereby incorporated by reference in their entiretyfor all purposes.

As used herein the term “spunbond fibers” refers to small diameterfibers of molecularly oriented polymeric material. Spunbond fibers maybe formed by extruding molten thermoplastic material as filaments from aplurality of fine, usually circular capillaries of a spinneret with thediameter of the extruded filaments then being rapidly reduced as in, forexample, U.S. Pat. No. 4,340,563 to Appel et al., and U.S. Pat. No.3,692,618 to Dorschner et al., U.S. Pat. No. 3,802,817 to Matsuki etal., U.S. Pat. Nos. 3,338,992 and 3,341,394 to Kinney, U.S. Pat. No.3,502,763 to Hartman, U.S. Pat. No. 3,542,615 to Dobo et al, and U.S.Pat. No. 5,382,400 to Pike et al. which are incorporated by reference intheir entirety for all purposes. Spunbond fibers are generally not tackywhen they are deposited onto a collecting surface and are generallycontinuous. Spunbond fibers are often about 10 microns or greater indiameter. However, fine fiber spunbond webs (having and average fiberdiameter less than about 10 microns) may be achieved by various methodsincluding, but not limited to, those described in commonly assigned U.S.Pat. No. 6,200,669 to Mormon et al. and U.S. Pat. No. 5,759,926 to Pikeet al.

SUMMARY OF THE INVENTION

The present invention is directed to a process for forming a fibrousnonwoven web with uniform, directionally-oriented projections. Theprocess involves providing a first forming surface defining a pluralityof openings therein and providing a second forming surface which ispervious to air. The first forming surface is overlaid atop the secondforming surface and the first forming surface is caused to travel in afirst direction at a first speed and the second forming surface iscaused to travel in the first direction at a second speed to cause aspeed differential between the first forming surface and the secondforming surface. A plurality of fibers are deposited onto the firstforming surface to form a fibrous nonwoven web while causing a portionof the plurality of fibers to extend through the openings in the firstforming surface and then contact the second forming surface to form aplurality of fibrous projections in the fibrous nonwoven web. The speeddifferential between the first and second forming surfaces causes theprojections to have a uniform, directional orientation relative to thefirst direction of travel of the first forming surface and once theprojections are formed and oriented the fibrous nonwoven web with theuniform, directionally-oriented projections is removed from the firstforming surface. If desired, the process can be modified by providing avacuum source beneath the second forming surface on a side of the secondforming surface opposite the first forming surface to aid in a movementof the fibers through the openings in the first forming surface andcontact the second forming surface.

As a result of the speed differential between the first and secondforming surfaces, one of the first and second forming surfaces can becaused to travel a differential distance “y” as defined herein which isbetween about two and about six inches (about 5.1 and about 15.2centimeters) further than the other of the first and second formingsurfaces travels over the same amount of time in a prescribed distance“D1” from when the material forming the fibrous nonwoven web is laiddown onto the first forming surface at a first location and a secondlocation when the heads of the formed projections are no longer incontact with the second forming surface. It is this difference indistance traveled due to the speed differential of the first and secondforming surfaces between the first and second locations that causes theuniform, directional orientation of the projections of the so-formedfibrous nonwoven web.

To create the speed differential between the two forming surfaces, theprocess can involve driving one of the first and second forming surfacesby frictional engagement with the other of the first and second formingsurfaces. Alternatively, the process can involve driving the firstforming surface in the first direction independently of the secondforming surface by having each of the forming surfaces driven by theirown separate drive devices.

An apparatus for forming a fibrous nonwoven web with uniform,directionally-oriented projections can include a first forming surfacedefining a plurality of openings therein with the first forming surfacebeing capable of moving in a first direction at a first speed along witha second forming surface which is pervious to air and capable of movingin a first direction at a second speed with the second forming surfacebeing positioned below the first forming surface and the second speedbeing different than the first speed. The apparatus includes a fiberdeposition apparatus positioned above and distanced from a surface ofthe first forming surface opposite the second forming surface and avacuum assist apparatus positioned below the second forming surface on aside of the second forming surface opposite the first forming surface.In certain applications, a coform apparatus can be used as the fiberdeposition apparatus.

In one embodiment of the apparatus the first forming surface and thesecond forming surface can be frictionally engaged with one another withone of the first and second forming surfaces being driven by the otherof the first and second forming surfaces due to the frictionalengagement between the first and second forming surfaces. In analternate embodiment of the apparatus, the first and second formingsurfaces can be driven in the first direction separately from oneanother by separate drive devices.

The first forming surface if desired can comprise a flexible beltdefining a plurality of holes therein and extending there through whichare spaced apart by a land area in the belt with it being preferablethat the land area is impervious to air emanating from the fiberdeposition apparatus.

Also disclosed herein is a fibrous nonwoven web having a top surface, anopposed bottom surface, a length, a width and a thickness with aplurality of uniform, directionally-oriented projections emanating fromthe top surface of the web. The fibrous nonwoven web, because of theuniform directional orientation of the projections, has a knap on thetop surface of the web which is smoother to the touch when engaged inone direction as opposed to the opposite direction. The projections eachhave a base portion with a vertical axis generally perpendicular to aplane formed by the top surface of the web and a head portion connectedto the base portion. This vertical axis is located at a position in thebase portion such that at least a portion of the base portion has alateral dimension that is equally spaced on either side of the verticalaxis. The head portion of the projection is asymmetrically locatedrelative to the base portion and the vertical axis such that the headportion has a lateral dimension which is skewed with respect to thevertical axis so that more of the head portion is located on one side ofsaid vertical axis than the base portion when viewing the head portionand the base portion from the same position. In addition, the headportion can form an overhang area with respect to said base portion.

The fibrous nonwoven web disclosed herein can be used in a wide varietyof products including a wipe and other cleaning products. It can also beused as a personal care absorbent article wherein as least a portion ofthe article comprises the disclosed fibrous nonwoven web. Such personalcare absorbent articles typically comprise a body side liner and agarment-facing sheet with an absorbent core disposed between the bodyside liner and the garment facing sheet. In such products it isdesirable that the body side liner comprise the fibrous nonwoven webdisclosed herein. Such personal care absorbent articles can be selectedfrom the group consisting of a diaper, a sanitary napkin, a childtraining pant and an adult incontinence device.

BRIEF DESCRIPTION OF THE FIGURES

A full and enabling disclosure of the present invention, including thebest mode thereof to one skilled in the art, is set forth moreparticularly in the remainder of the specification, which includesreference to the accompanying figures, in which:

FIG. 1 is a perspective view of one embodiment of a fibrous nonwoven webwith uniform, directionally-oriented projections according to thepresent invention.

FIG. 2 is a cross-section of the material shown in FIG. 1 taken alongline 2-2 of FIG. 1 showing a single oriented projection according to thepresent invention.

FIG. 3 is a schematic side view of a process and apparatus according tothe present invention for forming a fibrous nonwoven web with uniform,directionally-oriented projections according to the present invention.

FIG. 4 is a perspective view of a representative portion of a firstforming surface of an apparatus according to the present invention.

FIG. 5 is a photo of a cross-sectional view of the material according tothe present invention described in Example 1.

FIG. 6 is a photo of a cross-sectional view of the material according tothe present invention described in Example 2.

FIG. 7 is a photo of a cross-sectional view of the material described inComparative Example 1.

FIG. 8 is a cutaway top plan view of a personal care absorbent article,in this case a diaper, which can employ the fibrous nonwoven web withuniform, directionally-oriented projections according to the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION Product Description

Reference now will be made to the embodiments of the invention, one ormore examples of which are set forth below. Each example is provided byway of an explanation of the invention, not as a limitation of theinvention. In fact, it will be apparent to those skilled in the art thatvarious modifications and variations can be made in the inventionwithout departing from the scope or spirit of the invention. Forinstance, features illustrated or described as one embodiment can beused on another embodiment to yield still a further embodiment. Thus, itis intended that the present invention cover such modifications andvariations as come within the scope of the appended claims and theirequivalents. When ranges for parameters are given, it is intended thateach of the endpoints of the range are also included within the givenrange. It is to be understood by one of ordinary skill in the art thatthe present discussion is a description of exemplary embodiments only,and is not intended as limiting the broader aspects of the presentinvention, which broader aspects are embodied exemplary constructions.

Turning to FIGS. 1 and 2 there is shown a fibrous nonwoven web 10 withuniform, directionally-oriented projections according to the presentinvention. The web 10 has a top surface 12 an opposed bottom surface 14,a length 16, a width 18 and a thickness 20.

Emanating from the top surface 12 is a plurality of projections 30 whichare uniformly oriented in the same direction and separated by land area31. The projections 30 have a base portion 36 which defines a verticalaxis 38 which is generally perpendicular to a plane 40 defined by thetop surface 12 of the web 10. The projections 30 have a head portion 50connected to the based portion 36. The projections 30 have an overallheight 35 as measured from the top surface 12 of the web 10 to the topof the head portion 50 of the projection 30. This distance 35 can bedivided by a line 37 which is generally parallel to the top surface 12and the plane 40. The portion of the projection 30 above this line 37 isconsidered the head portion 50 and the portion of the projection 30below this line 37 is considered the base portion 36. Generally, thisline 37 will be drawn at a point that is below the main overhangingportion of the head portion 50 and thus below the point where the line62 contacts the head 50. See FIG. 2.

The vertical axis 38 is located at a position in the base portion 36such that the base portion 36 has a lateral dimension 52 that is equallyspaced on either side of the vertical axis 38 when the projection isviewed from a side such as is shown in FIG. 2. By “equally spaced” it ismeant that the vertical axis 38 can be positioned such that the lateraldimension 52 (which is determined below the line 37) can be divided intoa left portion 52 a and a right portion 52 b and the dimensions of thesetwo portions (52 a and 52 b) are within plus or minus 10 percent of oneanother.

In contrast, the head portion 50 of the projection 30 has a lateraldimension 54 which is located above the line 37 and which has a leftportion 54 a and a right portion 54 b relative to the vertical axis 38.As can be seen from FIG. 2, the head portion 50 is asymmetricallylocated with respect to the vertical axis 38 and the base portion 36such that the head portion 50 is skewed with respect to the verticalaxis 38 with more of the lateral dimension 54 being located on one side(in this case 54 a) of the vertical axis 38 than the other side (in thiscase 54 b) when viewing the lateral dimensions 52 and 54 from the sameposition.

As a result of this vertical skewing of the projections 36, there iscreated an overhang area 60 such as is shown in FIG. 2. This overhangarea 60 can be seen when viewing the projections 36 from the side. InFIG. 2, the overhang area 60 is defined by drawing a vertical line 62which is tangent to a portion of the head portion 50 (the overhangingedge 64), which does not intersect a portion of the head portion 50, andwhich is also generally parallel to the vertical axis 38. The overhandarea 60 is bounded by the line 62, the side 63 of the projection 30 andif need be the top surface 12 of the web 10.

Due to the nature of the equipment and process by which the web 10 ismade, the overhang areas 60 will be created in a direction which isgenerally parallel to the machine direction (MD) in which the web 10 ismade in the process and apparatus such as is shown in FIG. 3 of thedrawings. As explained in more detail below, depending on the relativespeed of the two forming surfaces used to form the projections 30, theoverhang areas 60 and the skewing of the head portions 50 will beparallel to the machine direction movement 148 and formation of the web10. If the first forming surface 140 of the apparatus 130 is movingfaster that the second forming surface 150, the overhanging edge 64 willpoint in the opposite direction of the machine direction 148 of theapparatus 130 in FIG. 3. Conversely, if the first forming surface 140 ofthe apparatus 130 is moving slower that the second forming surface 150,the overhanging edge 64 will point in the same direction as the machinedirection 148 of the apparatus 130 in FIG. 3. Thus, when it is said thatthe direction of the orientation of the projections 30 is “uniform” itis meant that in a measured area of the top surface 12 of the web 10, atleast 70 percent of the projections 30 are slanted to the same side ofthe vertical axis 38.

The web 10 can be made from a variety of materials including meltblownmaterials, coform materials, air-laid materials, bonded-carded webmaterials, hydroentangled materials, spunbond materials and the like,and can comprise synthetic or natural fibers. A preferred material is acoform web.

The fibrous nonwoven web 10 may be used as a wet wipe, and in particularbaby wipes. Different physical characteristics of the fibrous nonwovenweb may be varied to provide the best quality wet wipe. For example,formation, diameter of meltblown fibers, the amount of lint, opacity andother physical characteristics of the fibrous nonwoven web may bealtered to provide a useful wet wipe for consumers.

Typically, the fibrous nonwoven web 10 is a combination of meltblownfibrous materials and secondary fibrous materials. The relativepercentages of the meltblown fibrous materials and secondary fibrousmaterials in the web can vary over a wide range depending on the desiredcharacteristics of the fibrous nonwoven web. For example, fibrousnonwoven webs can have from about 20 to about 60 weight percent (wt. %)of meltblown fibrous materials and from about 40 to 80 wt. % ofsecondary fibers. Desirably, the weight ratio of meltblown fibrousmaterials to secondary fibers can be from about 20/80 to about 60/40.More desirably, the weight ratio of meltblown fibrous materials fibersto secondary fibers can be from about 25/75 to about 40/60.

Generally speaking, the overall basis weight of the fibrous nonwoven web10 is from about 10 grams per square meter (gsm) to about 500 gsm, andmore particularly from about 17 gsm to about 200 gsm, and still moreparticularly from about 25 gsm to about 150 gsm. The basis weight of thefibrous nonwoven web may also vary depending upon the desired end use.For example, a suitable fibrous nonwoven web for wiping the skin maydefine a basis weight of from about 30 to about 80 gsm and desirablyabout 45 to about 75 gsm. The basis weight (in grams per square meter,g/m2 or gsm) is calculated by dividing the dry weight (in grams) by thearea (in square meters).

One approach in making the fibrous nonwoven web 10 is to mix meltblownfibrous materials with one or more types of secondary fibrous materialsand/or particulates. The mixture is collected in the form of fibrousnonwoven web which may be bonded or treated to provide a coherentnonwoven material that can take advantage of at least some of theproperties of each component. These mixtures are referred to as “coform”materials because they are formed by combining two or more materials inthe forming step into a single structure.

Meltblown fibrous materials suitable for use in the fibrous nonwoven webinclude polyolefins, for example, polyethylene, polypropylene,polybutylene and the like, polyamides, olefin copolymers and polyesters.In accordance with a particularly desirable embodiment, the meltblownfibrous materials used in the formation of the fibrous nonwoven web arepolypropylene. See for example WO 2011/034523 for additional informationon suitable polymers for the meltblown fibers which is incorporatedherein for all purposes in its entirety.

The fibrous nonwoven web also includes one or more types of secondaryfibrous materials to form the nonwoven web. Any secondary fibrousmaterial may generally be employed in the coform nonwoven structure,such as absorbent fibers, particles, etc. In one embodiment, thesecondary fibrous material includes fibers formed by a variety ofpulping processes, such as kraft pulp, sulfite pulp, thermomechanicalpulp, etc. The pulp fibers may include softwood fibers having an averagefiber length of greater than 1 millimeter (mm) and particularly fromabout 2 to about 5 mm based on a length-weighted average. Such softwoodfibers can include, but are not limited to, northern softwood, southernsoftwood, redwood, red cedar, hemlock, pine (e.g., southern pines),spruce (e.g., black spruce), combinations thereof, and so forth.Exemplary commercially available pulp fibers suitable include thoseavailable from Weyerhaeuser Co. of Federal Way, Wash. under thedesignation “Weyco CF-405.” Hardwood fibers, such as eucalyptus, maple,birch, aspen, and so forth, can also be used. In certain instances,eucalyptus fibers may be particularly desired to increase the softnessof the web. Eucalyptus fibers can also enhance the brightness, increasethe opacity, and change the pore structure of the web to increase itswicking ability. Moreover, if desired, secondary fibers obtained fromrecycled materials may be used, such as fiber pulp from sources such as,for example, newsprint, reclaimed paperboard, and office waste. Further,other natural fibers can also be used, such as abaca, sabai grass,milkweed floss, pineapple leaf, and so forth. In addition, in someinstances, synthetic fibers can also be utilized. Wood pulp fibers areparticularly preferred as a secondary fibrous material because of lowcost, high absorbency and retention of satisfactory tactile properties.

Besides or in conjunction with pulp fibers, the secondary fibrousmaterial may also include a superabsorbent that is in the form offibers, particles, gels, etc. Generally speaking, superabsorbents arewater-swellable materials capable of absorbing at least about 20 timesits weight and, in some cases, at least about 30 times its weight in anaqueous solution containing 0.9 wt. % sodium chloride. Thesuperabsorbent may be formed from natural, synthetic and modifiednatural polymers and materials. Examples of synthetic superabsorbentpolymers include the alkali metal and ammonium salts of poly(acrylicacid) and poly(methacrylic acid), poly(acrylamides), poly(vinyl ethers),maleic anhydride copolymers with vinyl ethers and alpha-olefins,poly(vinyl pyrrolidone), poly(vinylmorpholinone), poly(vinyl alcohol),and mixtures and copolymers thereof. Further, superabsorbents includenatural and modified natural polymers, such as hydrolyzedacrylonitrile-grafted starch, acrylic acid grafted starch, methylcellulose, chitosan, carboxymethyl cellulose, hydroxypropyl cellulose,and the natural gums, such as alginates, xanthan gum, locust bean gumand so forth. Mixtures of natural and wholly or partially syntheticsuperabsorbent polymers may also be useful. Particularly suitablesuperabsorbent polymers are HYSORB 8800AD (BASF of Charlotte, N.C. andFAVOR SXM 9300 (available from Evonik Stockhausen of Greensboro, N.C.).

The secondary fibrous materials are interconnected by and held captivewithin the microfibers by mechanical entanglement of the microfiberswith the secondary fibrous materials, the mechanical entanglement andinterconnection of the microfibers and secondary fibrous materialsforming a coherent integrated fiber structure. The coherent integratedfiber structure may be formed by the microfibers and secondary fibrousmaterials without any adhesive, molecular or hydrogen bonds between thetwo different types of fibers. The material is formed by initiallyforming a primary air stream containing the meltblown microfibers,forming a secondary air stream containing the secondary fibrousmaterials, merging the primary and secondary streams under turbulentconditions to form an integrated air stream containing a thoroughmixture of the microfibers and secondary fibrous materials, and thendirecting the integrated air stream onto a forming surface to air formthe fabric-like material. The microfibers are in a soft nascentcondition at an elevated temperature when they are turbulently mixedwith the pulp fibers in air.

In certain embodiments the web 10 may be used as a “wet” or“premoistened” wipe in that it contains a liquid solution for cleaning,disinfecting, sanitizing, etc. The particular liquid solutions are notcritical and are described in more detail in U.S. Pat. Nos. 6,440,437 toKrzysik et al.; 6,028,018 to Amundson et al.; 5,888,524 to Cole;5,667,635 to Win et al.; and 5,540,332 to Kopacz et al., which areincorporated herein in their entirety by reference thereto for allpurposes. The amount of the liquid solution employed may depend upon thetype of wipe material utilized, the type of container used to store thewipes, the nature of the cleaning formulation, and the desired end useof the wipes. Generally, each wipe contains from about 150 to about 600wt. % and desirably from about 300 to about 500 wt. % of a liquidsolution based on the dry weight of the nonwoven structure.

Process and Apparatus Description

Turning to FIG. 3 of the drawings there is shown a process and apparatus130 for forming a fibrous nonwoven web 10 with directionally orientedprojections 30 according to the present invention. The apparatus 130includes a first forming surface 140 and a second forming surface 150.The first forming surface 140 is positioned above or atop the secondforming surface 150 in the area where web formation takes place. In FIG.3, the first forming surface 140 is a flexible mat or belt with aplurality of apertures or holes 142 defined therein as also shown in thepartial view of the first forming surface 140 shown in FIG. 4. While theland areas 144 of the surface 140 can be air permeable or impermeable,it is desirable that the land areas 144 not be permeable to air toincrease the suction effect through the holes 142 caused by the vacuumassist 160 positioned below the first and second forming surfaces (140and 150).

Rubberized mats or endless belts have been found to work particularlywell as the first forming surface 140. Such mats are available from F.N.Sheppard and Company of Erlanger, Ky. They are vulcanized endless beltstreated with release coatings. The belt material must be chosen to beheat resistant and compatible with the polymers being used. Forpolyolefin fibers, urethane coatings work well. Belt thicknessestypically range between about 1.6 and about 5.9 millimeters (mm). Theholes in the belt used for the below examples had a staggered pattern ofcircular holes having a 0.25 inch (6.35 mm) diameter with acenter-to-center spacing between holes in each row of 0.38 inches (9.65mm). Staggered length between rows was 0.19 inches (4.83 mm) as measuredfrom edge-to-edge. To facilitate processing, the belt had anunperforated border on its side edges of approximately 2.63 inches (66.8mm). While the holes used for the below examples were circular, othershapes can also be used. It should be appreciated that the foregoingdescription is of one particular embodiment of a forming surface 140.Other materials and dimensions can be used depending upon the particularparameters desired in the web material 10 and projections 30. Forexample, if projections 30 with greater overall heights 35 are desired,thicker belt materials may be used. In addition, the spacing of theholes 142 and the shape of the holes 142 may be varied depending on theend needs of the web 10.

The first forming surface 140 is driven by a conventional drive assemblywhich for sake of simplicity is shown by one or more drive rolls 146 inFIG. 3. The drive rolls 146 cause the first forming surface 140 totravel in a first direction 148 shown by arrow 148 in FIG. 3 at a firstspeed. Such drive systems are well known to those of ordinary skill inthe art.

The second forming surface 150 is positioned below the first formingsurface 140 and is air permeable so as to enable the vacuum assistapparatus 160 to draw the fibers of the fibrous nonwoven web 10 downinto the holes 142 and at least partially contact the top surface 152 ofthe second forming surface 150. It is desirable that the second formingsurface 150 be driven by its own drive assembly which for sake ofsimplicity is shown by one or more drive rolls 156. The drive roll orrolls 156 causes the second forming surface to travel in the same firstdirection 148 but at a second speed which causes a speed differential tobe created between the first forming surface 140 and the second formingsurface 150. Again, such drive systems are well known to those ofordinary skill in the art.

Typically the second forming surface 150 is a woven wire mesh structuresuch as is available from Albany International Company of Rochester,N.H. The spacing of the wires in the wire mesh can be varied but thewire mesh must be sufficiently open so as to allow a sufficient vacuumto be pulled by the vacuum assist apparatus 160. Exemplary of these wireweave geometry forming surfaces is the forming wire FORMTECH™ 6manufactured by Albany International Co. of Rochester, N.H. Such a wirehas a “mesh count” of about six strands by six strands per square inch(about 2.4 by 2.4 strands per square centimeter) resulting in about 36foramina or “holes” per square inch (about 5.6 per square centimeter).The FORMTECH™ 6 wire is made from polyester and has a warp diameter ofabout 1 millimeter, a shute diameter of about 1.07 millimeters, anominal air permeability of approximately 41.8 m3/min (1475 ft3/min), anominal caliper of about 0.2 centimeters (0.08 inch) and an open area ofapproximately 51%. Another exemplary forming surface available from theAlbany International Co. is the forming wire FORMTECH™ 10, which has amesh count of about 10 strands by 10 strands per square inch (about 4 by4 strands per square centimeter) resulting in about 100 foramina or“holes” per square inch (about 15.5 per square centimeter). Stillanother suitable forming wire is FORMTECH™ 8, which has an open area of47% and is also available from Albany International Co. Of course, otherforming wires and surfaces (e.g., drums, plates, etc.) may be employed.Also, surface variations may include, but are not limited to, alternateweave patterns, alternate strand dimensions, release coatings (e.g.,silicones, fluorochemicals, etc.), static dissipation treatments, andthe like. Still other suitable foraminous surfaces that may be employedare described in U.S. Patent Application Publication No. 2007/0049153 toDunbar et al. which is incorporated herein by reference thereto for allpurposes.

As stated previously, the fibrous nonwoven web 10 can be formed from anynumber of fibrous structures such as coform materials, carded staplefibers, meltblown webs, spunbond webs and other fibrous web formingprocesses. The key aspect is that the fibers on the top surface 147 ofthe first forming surface 140 are capable of being drawn down into theholes 142 such that they come in contact with the top surface 152 of thesecond forming surface 150 so that the speed differential between thetwo forming surfaces can cause the projections 30 to skew and take on auniform directional orientation relative to the first direction ofmovement 148 of the first forming surface 140.

In FIG. 3, the fibrous nonwoven web 10 is formed from a coform materialwhich is a mixture of meltblown fibers and wood pulp fibers. The formingapparatus 170, which in this case is a coform apparatus 170, includes acentral source 172 of pulp fibers and two meltblown dies 174 whichtogether create meltblown fibers which mix with the pulp fibers to forma coform mix 176 which is deposited down onto the top surface 147 of thefirst forming surface 140. As the first forming surface 140 moves in thefirst direction 148 at its first speed, the coform mix 176 encountersthe vacuum 160 which, along with the force of deposition, causes aportion of the coform fiber mix 176 to be drawn down into the apertures142 in the first forming surface 140 to form the projections 30. Due tothe fact that the first forming surface 140 is positioned atop of thesecond forming surface 150, the fibers of the projections 30 comingthrough the apertures 142 in the first forming surface 140 contact thetop surface 152 of the second forming surface 150 but are prevented frombeing drawn down into the vacuum 160. It should be noted that otherconfigurations of meltblown and secondary fiber feeds also may be usedas well as multiple banks of coform or other fibrous structures,especially when higher line speeds or higher basis weights are beingused. Some examples of such coform techniques are disclosed in U.S. Pat.Nos. 4,100,324 to Anderson et al.; 5,350,624 to Georger et al.; and5,508,102 to Georger et al., as well as U.S. Patent ApplicationPublication Nos. 2003/0200991 to Keck et al. and 2007/0049153 to Dunbaret al., all of which are incorporated herein in their entirety byreference thereto for all purposes.

As a result of the speed differential between the two forming surfaces(140 and 150) and the frictional engagement of the fibers of theprojections 30 in contact with the second forming surface 150, thesymmetrically-formed projections 30 begin to uniformly skew in the samedirection. In the embodiment of FIG. 3, the first speed of the firstforming surface 140 is slower than the second speed of the secondforming surface 150. Consequently, the head portions 50 of theprojections 30 are skewed forward to form leading hooks 33 as are shownschematically on the left side of the process in FIG. 3 as the resultantfibrous nonwoven web 10 is wound up on take-up roll 180. Alternatively,if the speed differential is such that the second speed of the secondforming surface 150 is slower than that of the first speed of the firstforming surface 140, the projections 30 in the fibrous web 10 will skewin the opposite direction (that is, opposite of the direction of arrow148 in FIG. 3) as the web 10 is wound up on take-up roll 180. In eitherspeed configuration, the degree of directional bending of theprojections 30 can be controlled in part by way of the speeddifferential between the two forming surfaces (140 and 150).

In the embodiment of the process and apparatus shown in FIG. 3 of thedrawings, the first forming surface 140 and the second forming surface150 are each driven independently of one another so the separate drivesystems can be separately controlled to vary the speed differential andthus the amount of skewing or orienting of the projections 30 in the web10. An alternate embodiment, not shown, is to drive one of the twoforming surfaces and not the other (140 or 150) and allow the twoforming surfaces to contact one another such that the frictionalengagement of the two forming surfaces drives the other surface. It hasbeen found that there is enough friction between the two surfaces todrive the non-driven one but there is also enough slip to cause thenon-driven surface to travel at a different speed than the drivensurface thereby creating the same effect needed to skew or orient theprojections 30 in the web 10. In this regard, it was generally foundthat driving the second forming surface 150 and not driving the firstforming surface 140 worked best. In addition, by adjusting the rollers146 and 156, the amount of gap, if any, and thus the frictionalengagement of the two surfaces (140 and 150) can be adjusted to controlthe amount of engagement and drag between the two surfaces.

The line speeds of the two forming surfaces (140 and 150) will varydepending upon the materials being used to form the fibrous web 10, thebasis weight needed, the amount of vacuum being used and otherparameters commonly associated with forming such webs including coformwebs. For the basis weights described herein, generally the line speedswill range between about 30 meters per minute (100 feet per minute) andabout 600 meters per minute (2,000 feet per minute), desirably betweenabout 90 meters per minute (300 feet per minute) and about 378 metersper minute (1240 feet per minute) and more desirably between about 198meters per minute (650 feet per minute) and about 304 meters per minute(1000 feet per minute).

The meltblown fibers used in the coform process assist in maintainingthe orientation of the projections 30 once the web 10 is formed. It isbelieved that because the meltblown fibers crystallize at a relativelyslow rate, they are soft upon deposition onto the first and secondforming surfaces (140 and 150). Thus the speed differential between thefirst and second forming surfaces creates a drag on the head portion 50of the projections 30 which, by the time the web 10 is removed from theforming surfaces, has set in the oriented formation. After the fiberscrystallize, they are then able to hold the shape and maintain theorientation.

The degree of orientation can be varied by varying the amount of thespeed differential between the first and second forming surfaces (140and 150) and thus the amount of distance that one forming surface coversversus the other in the prescribed amount of time it takes the firstforming surface 140 to travel the distance between the first location141 and the second location 145 denoted as “D1” in FIG. 3. In thecontext of distance traveled, to form the projections 30, it isdesirable to cause one of the first 140 and second 150 forming surfacesto travel a distance “y” as defined herein which is between about 2inches (51 mm) and about six inches (152 mm) further than the other ofthe first and second forming surfaces, more preferably between about 3inches (76 mm) and about 5 inches (127 mm) and more preferably about 4inches (102 mm) and about 5 inches (127 mm). It should be appreciated,however, that speed and distance differentials outside this range canalso be used depending on the particular end use and the variance ofother parameters such as, for example, the polymers and fibers beingused, the deposition rate, the size of the holes in the first formingsurface, the dwell time of the web on the forming surfaces, the gap, ifany, between the forming surfaces and the amount of vacuum being used todraw the fibers down onto the forming surfaces.

For the uses described herein, the projections will typically haveoverall heights 35 in the range of about 0.25 millimeters (0.01 inches)to at least about 9 millimeters (0.35 inches), and in some embodiments,from about 0.5 millimeters (0.02 inches) to about 3 millimeters (0.12inches). Generally speaking, the projections 30 are filled with fibersand thus have desirable resiliency useful for wiping and scrubbing.

Product Applications

One of the advantages of the web 10 according to the present inventionis that it has two different aesthetic feels depending on the directionin which the material is contacted or engaged. Because of the uniformorientation of the projections 30, a knap is created on the top surface12 of the web which is perceptible to human touch and feel. If thematerial is rubbed or engaged in one direction, it has a rougher feelthat if rubbed or engaged in the opposite direction. This is the casewhen the overhanging edge 64 is the leading edge during the engagementprocess. Conversely, when the overhanging edge 64 is the trailing edgeduring the engagement process, the web 10 has a smoother feel.

The fibrous nonwoven web 10 may be used in a wide variety of articlesand uses. For example, the web may be incorporated into an “absorbentarticle” that is capable of absorbing water or other fluids. Examples ofsome absorbent articles include, but are not limited to, personal careabsorbent articles, such as diapers, training pants, absorbentunderpants, incontinence articles, feminine hygiene products (e.g.,sanitary napkins), swim wear, baby wipes, mitt wipes, and so forth;medical absorbent articles, such as garments, fenestration materials,underpads, bedpads, bandages, absorbent drapes, and medical wipes; foodservice wipers; clothing articles; pouches, and so forth. Otherapplications include facial and cosmetic wipes, both wet and dry, aswell as household cleaning wipes both as individual sheets and asdisposable attachments for cleaning tools such as mops and otherhandheld cleaning devices. Materials and processes suitable for formingsuch articles are well known to those skilled in the art.

Personal care absorbent articles typically have certain key componentswhich may employ the web 10 of the present invention. Turning to FIG. 8there is shown a basic diaper design 200. Typically such products 200will include a body side liner or skin-contacting material 202, agarment-facing material or sheet also referred to as a backsheet 204 andan absorbent core 206 disposed between the body side liner 202 and thegarment facing sheet 204. In addition, it is also common for the productto have an optional layer 208 which is commonly referred to as a surgeor transfer layer disposed between the body side liner 202 and theabsorbent core 206.

The web 10 according to the present invention may be used as all or aportion of any one or all of these aforementioned components of suchpersonal care products 200 including one of the external surfaces (202or 204). For example, the web 10 may be used as the body side liner 202in which case it is more desirable for the projections 30 to be facingoutwardly so as to be in a body contacting position in the product 200.The laminate 10 may also be used as the surge or transfer layer 208 oras the absorbent core 206 or a portion of the absorbent core 206.Finally, the web 10 may be used as the outermost side of the garmentfacing sheet 204 in which case it may be desirable to attach a liquidimpervious film or other material (not shown) to the bottom surface 14of the web 10.

EXAMPLES

In the following examples, Examples 1 and 2 provide specific informationregarding two embodiments of the process and fibrous nonwoven web 10 ofthe invention while Comparative Example 1 describes a similar processand resulting fibrous nonwoven web, but without the directionalorientation of the projections. In all three examples, the polymercomposition used in the production of the meltblown fibers is the sameand is as follows:

-   -   85% by weight Metocene MF650X, a propylene homopolymer having a        density of 0.91 g/cm³ and melt flow rate of 1200 g/10 minute        (230° C., 2.16 kg), which is available from Basell Polyolefins.    -   15% by weight Vistamaxx 2330, a propylene/ethylene copolymer        having a density of 0.868 g/cm³, meltflow rate of 290 g/10        minutes (230° C., 2.16 kg) which is available from ExxonMobil        Corp.

Also, in all 3 examples, the pulp fibers were fully treated southernsoftwood pulp obtained from the Weyerhaeuser Co. of Federal Way, Wash.under the designation “CF-405.”

To calculate the differential in distance traveled between the firstforming surface 140 and the second forming surface 150 and thus thedegree of directional orientation of the projections 30 in the web 10,the difference in travel of the two forming surfaces (140 and 150) mustbe measured over a prescribed distance. The distance used to make thismeasurement in the below examples was the distance between a first laydown point 141 on the first forming surface 140 and a second take-uppoint 145 on the first forming surface 140. See FIG. 3. The location ofthe first lay down point (first location 141) should be below thecentral-most set of die tips or other deposition device 172 of theapparatus 170. The location of the take up point (second location (145)is generally the point at which the heads 50 of the projections 30 ofthe fibrous nonwoven web 10 are no longer in contact with the topsurface 152 of the second forming surface 150. As shown in FIG. 3, thedistance between first location 141 and second location 145 is referredto as distance “D1”. In the time it takes the first forming surface 140to travel the distance D1, the second forming surface 150 will havetraveled a different distance “D2” which may be longer or shorter thanD1 depending on the speed of each forming surface. As this is a variabledistance depending on the speed differential of the two formingsurfaces, D2 is not shown in FIG. 3.

Referring again to FIG. 3 of the drawings, a pair of markers, firstmarker 141 a and second marker 141 b, are made on the respective upperforming surface 140 and the lower forming surface 150 at a firstlocation 141 directly below the point of fiber deposition from theapparatus 170. If more than one forming bank is being used, it isdesirable to make the point 141 coincide with the forming bank which isfurthest from the take-up roll 180. The markers 141 a and 141 b shouldbe in vertical alignment with one another and the first location 141marker. The marker for first location 141 should be placed at astationary location relative to the overall apparatus 130 as should thesecond location 145 marker as these are the two stationary referencepoints for the calculations set forth below and the constant distanceD1.

Any number of materials may be used to form the markers 141, 141 a, 141b and 145 including inks, paints, tapes, mechanical and electronicmarkers. Depending on the speeds of the forming surfaces (140 and 150),the markers may be visible with the naked eye and changes in therelative position of the markers may be measured with a ruler or similardevice. Alternatively, the markers may contain components (such asreflective surfaces or digital/electronic senders or sensors) which canbe tracked with electronic, photographic and/or other imaging andsensing devices.

For purposes of demonstrating how to calculate the difference indistance traveled by the two forming surfaces (140 and 150) betweenfirst location 141 and second location 145, assume that the firstforming surface 140 is moving faster than the second forming surface150. (The calculation is also valid for the reverse scenario.) Asmentioned previously, the distance D1 between first location 141 andsecond location 145 is a known and set distance. Distance D2 is thedistance that the second forming surface 150 will have moved (as trackedby the second marker 141 b) in the time “t” that the first formingsurface 140 moves distance D1 (that is the time that first marker 141 atakes to travel between first location 141 and second location 145). Thedifferential distance “y” that the first forming surface 140 and thusfirst marker 141 a travels as compared to the distance the secondforming surface 150 has traveled in the same amount of time “t” is equalto the equation y=D1-D2. Additionally, “S1” is the speed of the firstforming surface 140 and “S2” is the speed of the second forming surface150. Also, t=D1/S1 and t=D2/S2. Therefore, substituting for like valuesin the foregoing equations:

t=(D2/S2)=(D1−y)/S2) and so:

(D1/S1)=[(D1−y)/S2] and solving for y yields:

y=D1×[1−(S2/S1)].

As a result, the difference in distance that one forming surface travelsversus the other in the process is dependent on both the distance D1 andthe ratio of the speeds (S1 and S2) at which the two forming surfacesare traveling. In this regard, “y” will be a positive number when S1 isgreater than S2 (that is, first forming surface 140 is traveling fasterthan second forming surface 150), and “y” will be a negative number whenS1 is less than S2 (that is, first forming surface 140 is travelingslower than second forming surface 150). Consequently, the absolutevalue of “y” should be used.

In view of the above and in view of the examples below, the distancedifferential “y” as defined herein will typically be between about 2inches (51 mm) and about six inches (152 mm), alternately between about3 inches (76 mm) and about 5 inches (127 mm) and still further betweenabout 4 inches (102 mm) and about 5 inches (127 mm).

Example 1

A coform web was formed via a two-bank process in which each bankconsisted of two heated streams of meltblown fibers and a single streamof fiberized pulp fibers as described above and shown in FIGS. 3 and 4.Note that in FIG. 3 only a single bank apparatus 170 is shown but forthe below examples, two banks were used.

In the first bank (that is, the bank that deposits fibers directly ontothe top surface 147 of the first forming surface 140), the polypropyleneof each stream was supplied to respective meltblown dies at a rate of2.73 kg to 2.95 kg of polymer per 2.54 cm of die tip width per hour (5.0to 5.5 pounds of polymer per inch of die tip width per hour). Themeltblown dies were positioned such that the tips were 25.4 cm (10inches) horizontally from the pulp nozzle centerline and 25.4 cm (10inches) above the first forming surface 140. They were tilted inwardlytowards the pulp nozzle at an angle of 80° from the horizontal. The pulpnozzle was 15.24 cm (6 inches) above the first forming surface. The pulpwas delivered at a rate of 6.4 kg per 2.54 cm of pulp nozzle width perhour (14 pounds per inch of pulp nozzle width per hour).

In the second bank (that is, the bank that deposits fibers on top of theweb formed by the first bank), the polypropylene of each stream wassupplied to respective meltblown dies at a rate of 2.27 kg of polymerper 2.54 cm of die tip width per hour (5.0 pounds of polymer per inch ofdie tip width per hour). The meltblown dies were positioned such thatthe tips were 17.8 cm (7 inches) horizontally from the pulp nozzlecenterline and 17.8 cm (7 inches) above the first forming surface 140.They were tilted inwardly towards the pulp nozzle at an angle of 50°from the horizontal. The pulp nozzle was 24.1 cm (9.5 inches) above thefirst forming surface 140. The pulp was delivered at a rate of 2.3 kgper 2.54 cm of pulp nozzle width per hour (5 pounds per inch of pulpnozzle width per hour).

In total, the resulting fibrous web had a meltblown fiber content ofabout 52% and a pulp fiber content of about 48% on a weight percentbasis. The second forming surface 150 was an ELECTRATECH™ 56 (AlbanyInternational Co.) forming wire. To create the projections 30, the firstforming surface 140 was a rubber mat having a thickness of approximately2.65 millimeters (0.10 inch) and containing 6.35 mm (0.25 inch) diametercircular holes 142 arranged in a pattern similar to that shown in FIG. 4of the drawings. The spacing of the holes 142 was 9.53 mm (0.375 inches)from center to center in both the machine and cross directions. A vacuumbox 160 was positioned below the second forming surface 150 to aid indeposition of the fibers and the formation of the web and was set to avacuum level sufficient to draw the fibrous mixture from the first bankinto the holes 142 in the first forming surface 140. The vacuum levelwas also sufficient to draw a portion of the fibers that entered theholes 142 of the first forming surface 140 into contact with the secondforming surface 150. The second forming surface 150 was driven by adrive roll (one of the four rolls 156). The first forming surface 140was driven by contact with the second forming surface 150 and was notdriven independently of the second forming surface 150. To create thedirectional orientation of the projections 30, the first forming surface140 was run at a first speed of 195 meters per minute (640 feet perminute) and the second forming surface 150 was run at a second speed ofapproximately 194 meters per minute (637 feet per minute). The speedmismatch between the first and second forming surfaces resulted in thefirst forming surface 140 traveling 5.1 cm (2 inches) farther than thesecond forming surface 150 over the distance “D1” of 12.2 m (40 feet).Thus the distance differential value “y” was equal to 51 millimeter. Theresultant coform web 10 had a configuration similar to that shown inFIG. 1. A photographic, cross-sectional side view of the web is shown inFIG. 5.

Example 2

A coform web was formed via a two-bank process in which each bankconsisted of two heated streams of meltblown fibers and a single streamof fiberized pulp fibers as described above with respect to Example 1.

In the first bank (that is, the bank that deposits fibers directly ontothe top surface 147 of the first forming surface 140), the polypropyleneof each stream was supplied to respective meltblown dies at a rate of2.73 kg to 2.95 kg of polymer per 2.54 cm of die tip width per hour (6.0to 6.5 pounds of polymer per inch of die tip width per hour). Themeltblown dies were positioned such that the tips were 25.4 cm (10inches) horizontally from the pulp nozzle centerline and 25.4 cm (10inches) above the first forming surface 140. They were tilted inwardlytowards the pulp nozzle at an angle of 80° from the horizontal. The pulpnozzle was 15.2 cm (6 inches) above the first forming surface 140. Thepulp was delivered at a rate of 13.6 kg per 2.54 cm of pulp nozzle widthper hour (30 pounds per inch of pulp nozzle width per hour).

In the second bank (that is, the bank that deposits fibers on top of theweb formed by the first bank), the polypropylene of each stream wassupplied to respective meltblown dies at a rate of 2.3 kg of polymer per2.54 cm of die tip width per hour (5.0 pounds of polymer per inch of dietip width per hour). The meltblown dies were positioned such that thetips were 17.8 cm (7 inches) horizontally from the pulp nozzlecenterline and 17.8 cm (7 inches) above the first forming surface 140.They were tilted inwardly towards the pulp nozzle at an angle of 50°from the horizontal. The pulp nozzle was 24.1 cm (9.5 inches) above thefirst forming surface 140. The pulp was delivered at a rate of 2.3 kgper 2.54 cm of pulp nozzle width per hours (5 pounds per inch of pulpnozzle width per hour).

In total, the resulting fibrous web had a meltblown fiber content ofabout 39% and a pulp fiber content of about 61% on a weight percentbasis. To create the directional orientation of the projections 30, thefirst forming surface 140 was run at a first speed of 285 meters perminute (935 feet per minute) and the second forming surface 150 was runat a second speed of approximately 281 meters per minute (923 feet perminute). The speed mismatch between the first and second formingsurfaces resulted in the first forming surface 140 traveling 15.2 cm(6″-inches) farther than the second forming surface 150 over thedistance “D1” of 12.2 m (40 feet). Thus the distance differential value“y” was equal to 152 millimeter. The resultant coform web 10 had aconfiguration similar to that shown in FIG. 1. A photographic,cross-sectional side view of the web is shown in FIG. 6.

Comparative Example 1

Comparative example 1 was run with no speed differential between thefirst forming surface 140 and the second forming surface 150. The firstand second forming surfaces were driven independently, but at the samespeed of approximately 195 meters per minute (640 feet per minute). As aresult, no directional orientation of the projections was achieved andno overhang area was created. Further, the distance differential value“y” was equal to 0 millimeter due to their being no speed differentialbetween the two forming surfaces.

A coform web was formed via a two-bank process in which each bankconsisted of two heated streams of meltblown fibers and a single streamof fiberized pulp fibers as described above and shown in FIGS. 3 and 4.The forming conditions and delivery rates for the meltblown fibers andpulp were the same as in Example 1 resulting in a fibrous web with ameltblown fiber content of about 52% and a pulp fiber content of about48% on a weight percent basis. A photographic, cross-sectional side viewof the web is shown in FIG. 7.

As can be seen from FIGS. 5, 6 and 7, due to the speed differential andthus the difference in the distance traveled by the first formingsurface 140 versus the second forming surface 150, a series of uniform,directionally-oriented projections 30 could be formed in the fibrousnonwoven web 10. See FIGS. 5 an 6. Without the speed differential and/orinsufficient contact between the head portions 50 of the projections 30with the top surface 152 of the second forming surface 150, nodirectional orientation occurs. Also it can be seen in comparing thematerials of FIGS. 5 and 6 that with increased speed differential andtravel distance differential of the two forming surfaces between fiberlaydown and web take-up (Example 2 as compared to Example 1), greaterdirectional orientation and overhang can be achieved with respect to theprojections 30.

While the invention has been described in detail with respect to thespecific embodiments thereof, it will be appreciated that those skilledin the art, upon attaining an understanding of the foregoing, mayreadily conceive of alterations to, variations of, and equivalents tothese embodiments. Accordingly, the scope of the present inventionshould be assessed as that of the appended claims and any equivalentsthereto.

What is claimed is:
 1. A process for forming a fibrous nonwoven web withuniform, directionally-oriented projections comprising: providing afirst forming surface defining a plurality of openings therein;providing a second forming surface which is pervious to air; overlayingsaid first forming surface atop said second forming surface; causingsaid first forming surface to travel in a first direction at a firstspeed; causing said second forming surface to travel in said firstdirection at a second speed to cause a speed differential between saidfirst forming surface and said second forming surface; depositing aplurality of fibers onto said first forming surface to form a fibrousnonwoven web; causing a portion of said plurality of fibers to extendthrough said openings in said first forming surface and contact saidsecond forming surface to form a plurality of fibrous projections insaid fibrous nonwoven web; said speed differential causing saidprojections to have a uniform, directional orientation relative to saidfirst direction of travel of said first forming surface; and removingsaid fibrous nonwoven web with said uniform, directionally-orientedprojections from said first forming surface.
 2. The process of claim 1which further includes providing a vacuum source beneath said secondforming surface on a side of said second forming surface opposite saidfirst forming surface to aid in a movement of said fibers through saidopenings in said first forming surface and contact said second formingsurface.
 3. The process of claim 1 which further includes causing saidfirst and second forming surfaces to travel at a distance differential“y” as defined herein of between about 51 millimeters (2 inches) andabout 152 millimeters (6 inches).
 4. The process of claim 2 whichfurther includes driving one of said first and second forming surfacesby frictional engagement with the other of said first and second formingsurfaces.
 5. The process of claim 2 which further includes driving saidfirst forming surface in said first direction independently of saidsecond forming surface.
 6. An apparatus for forming a fibrous nonwovenweb with uniform, directionally-oriented projections comprising: a firstforming surface defining a plurality of openings therein, said firstforming surface being capable of moving in a first direction at a firstspeed; a second forming surface which is pervious to air capable ofmoving in a first direction at a second speed, said second formingsurface being positioned below said first forming surface, said secondspeed being different than said first speed; a fiber depositionapparatus positioned above and distanced from a surface of said firstforming surface opposite said second forming surface; and a vacuumassist apparatus positioned below said second forming surface on a sideof said second forming surface opposite said first forming surface. 7.The apparatus of claim 6 wherein said fiber deposition apparatus is acoform apparatus.
 8. The apparatus of claim 6 wherein said first formingsurface and said second forming surface are frictionally engaged withone another and one of said first and second forming surfaces is drivenby the other of said first and second forming surfaces due to saidfrictional engagement between said first and second forming surfaces. 9.The apparatus of claim 6 wherein said first and second forming surfacesare driven in said first direction separately from one another.
 10. Theapparatus of claim 6 wherein said first forming surface comprises aflexible belt defining a plurality of holes therein and extending therethrough which are spaced apart by a land area in said belt, said landarea being impervious to air emanating from said fiber depositionapparatus.
 11. A fibrous nonwoven web having a top surface, an opposedbottom surface, a length, a width and a thickness, a plurality ofuniform, directionally-oriented projections emanating from said topsurface of said web.
 12. The fibrous nonwoven web of claim 11 whereinsaid web has a knap on said top surface due to said projections suchthat it is smoother to the touch when engaged in one direction asopposed to the opposite direction.
 13. The fibrous nonwoven web of claim11 wherein said projections each have a base portion with a verticalaxis generally perpendicular to a plane formed by said top surface ofsaid web and a head portion connected to said base portion, saidvertical axis being located at a position in said base portion such thatsaid base portion has a lateral dimension that is equally spaced oneither side of said vertical axis, said head portion of said projectionbeing asymmetrically located relative to said base portion and saidvertical axis such that said head portion has a lateral dimension whichis skewed with respect to said vertical axis so that more of said headportion is located on one side of said vertical axis than said baseportion when viewing said head portion and said base portion from thesame position.
 14. The fibrous nonwoven web of claim 13 wherein saidhead portion forms an overhang area with respect to said base portion.15. A wipe comprising the fibrous nonwoven web of claim
 11. 16. Apersonal care absorbent article comprising the fibrous nonwoven web ofclaim
 11. 17. A personal care absorbent article comprising a body sideliner and a garment-facing sheet with an absorbent core disposed betweensaid body side liner and said garment facing sheet wherein said bodyside liner comprises the fibrous nonwoven web of claim
 11. 18. Thepersonal care absorbent article of claim 17 wherein said article isselected from the group consisting of a diaper, a sanitary napkin, achild training pant and an adult incontinence device.